1. Technical Field of the Invention
The present invention relates to a unit for accommodating electronic components and in particular, to such a unit which is capable of suppressing harmful effects caused by liquid such as steam, rain drops which might have intruded into the inside thereof.
2. Description of the Related Art
As one conventional electronic-component accommodating unit, Japanese Patent Application Laid-Open Publication NO. 10-51158 discloses as an electronic control unit for enhancing waterproof property.
The electronic control unit as disclosed in this Japanese Patent Application Laid-Open Publication is a case consisting of a box and a cover which houses a circuit board on which electronic components are implemented. A rib which protrudes from the edge section of the cover toward the inner face side of the box when the opening portion of the box is covered with the cover is integrally provided, and resin is filled inside the box so that the resin is in contact with the rib. Doing this prevents liquid from intruding into the electronic components and the circuit board which are housed in the case, even if a gap is generated at a joint between the cover and the box and liquid has intruded inside therethrough. This is because the rib of the cover is in contact with the resin in the box at a portion just inside of the gap. However, although the electronic control unit disclosed in Japanese Patent Application Laid-Open Publication NO. 10-51158 enables the prevention of liquid from intruding into the electronic components and the circuit board, there is a need for providing a rib in the cover, thereby causing a disadvantage that the size of the electronic control unit increases.